Grapevine cv. Sugratwelve

ABSTRACT

A grapevine cv. Sugratwelve that is a mutation of the Sugraone grapevine and that is characterized by its seedless grapes which mature two days earlier than Sugraone grapes and differ markedly from Sugraone grapes in cluster count per vine, cluster weight, berry weight, berry length, berry diameter, sugar content and titratable acid levels.

This invention relates to the discovery and asexual propagation of a newvariety of hybrid grapevine Vitis vinifera cv. Sugratwelve. TheSugratwelve variety bears seedless berries that have a pleasing tasteand other desirable table grape characteristics. The Sugratwelve varietywas discovered by Harry Joe Newby, Jr., as a single cordon mutation of aSugraone grapevine (U.S. Plant Pat. No. 3,106) growing in a commercialvineyard near Thermal, Calif. David W. Cain and Kevin S. Andrewasexually propagated the new variety from a cutting taken from themutation and demonstrated its stability from hardwood cuttings andgraftings. The Sugratwelve grapevine maintains its distinguishingcharacteristics as hereinafter set out through successive asexualpropagations using hardwood cuttings and grafting techniques.

The new Sugratwelve variety may be distinguished from its parentSugraone and also from other presently available commercial cultivars bythe following combination of characteristics: it matures at about thesame time (about two days earlier) as Sugraone and about 10 to 15 daysbefore the Thompson Seedless variety; the berries are somewhat similarin shape to those of the Thompson Seedless variety and are moreelongated in shape than those of the Sugraone and Perlette varieties.The fruit has a tougher skin and a more crisp flesh texture and alighter greenish creamy white skin color than either Thompson Seedlessor Centennial Seedless which tend to have a deeper green skin color. Aswill be described in greater detail hereinafter, the Sugratwelve andSugraone grapevines and fruit differ markedly as to cluster count pervine, cluster weight, berry weight, berry length, berry diameter, sugarcontent and titratable acid levels.

In the accompanying drawings, FIG. 1 illustrates, in full color, atypical cluster of berries, stem section, young shoot and mature leafblade of the new grapevine. FIG. 2 illustrates a Sugraone variety berrycluster (on left) and a Sugratwelve variety berry cluster (on right).

Throughout this specification, color names beginning with a small lettersignify that the name of the color, as used in common speech, is aptlydescriptive. Color names beginning with capital letters designate valuesbased on The R.H.S. Colour Chart of The Royal Horticultural Society ofLondon, England.

The descriptive matter which follows pertains to grapevines of the newSugratwelve variety grown near Wasco, in Kern County, Calif., in 1990and 1991, and is believed to apply to plants of the variety grown undersimilar conditions of soil and climate elsewhere.

VINE

The vine on its own root is large in size and of medium vigor. Thefoliage is of medium density. The vines are hardy, productive, bearingtheir fruit regularly.

The trunk is of average thickness and bears long straps. The surface isof medium texture and about Greyed-Orange 174C in color. The canes areaverage in caliper and are of medium surface texture. Canes are about180 cm. long and about 1.5 cm. wide at the node. Nodes are rounded andof average length. The average distance between nodes is about 7 cm.

SHOOTS

Shoots exhibit strong vigor during flowering. Flowering shoots aresemi-erect when not tied. The dorsal and ventral sides of both theinternodes and nodes are green with red stripes, about Greyed-Purple183B in color. Anthocyanin coloration is absent from or very weak in theimmature shoot buds.

Young shoot tips are half-open in form. Very weak anthocyanin colorationis distributed as piping at the edges of the young shoot tips. Bothprostrate and erect hairs are present in average densities at the shoottips.

Woody shoots are circular in cross section. The surface of woody shootsis ribbed and about Greyed-Orange 165D in color.

Lenticels are absent. Erect hairs are dense at the nodes and no hairsare present at the internodes.

Tendrils, averaging about 20 cm. in length and medium thickness arediscontinuously distributed on the shoot at full flower. Tendrils areabout Yellow-Green 145B in color. Tendrils are trifurcated in form.

Leaf producing buds are slightly pointed and of average size--about 0.4cm. Buds are markedly held out at an angle of about 60°. Basal buds areunfruitful and mid shoot and distal buds are fruitful and seldom dead.

LEAVES

In general, the upper surface of a young leaf is about Yellow-Green 144Ain color. Prior to flowering anthocyanin is weak or absent in the distalleaves. On the lower surface of the young leaves, both prostrate anderect hairs are very sparsely distributed between veins and sparsely onthe veins.

Mature leaves have a generally circular outline and an involute profile.Leaves are of average size (about 13 cm. long and about 18 cm. wide) andthe blades are of medium size, pentagonal in shape and have 3 lobes. Theleaf blade tip lies in the plane of the leaf. The leaf margin showsmedium undulation. The leaf apex is cuspidate; the leaf base isV-shaped. The leaf blade has undulations between the main and lateralveins but only near the petiole. Teeth are convex on both sides. Theupper leaf sinuses are closed.

The upper surface of the leaf is near Yellow-Green 137A in color.Anthocyanin coloration is absent on the main veins of the upper leafsurface. The upper leaf surface is rugose in texture, weakly glossy andhas a dull surface appearance; Pubescence is absent. Blistering on upperside surface of blade is absent or very weak. Blades are goffered.

The lower leaf surface is about Green 137C in color, average inglossiness and with no pubescence. Anthocyanin coloration of the mainveins on the lower leaf surface is absent. The lower leaf surface issmooth in texture and semi-glossy in surface appearance.

The petiole is shorter than the middle vein. There are no erect hairspresent on the petiole. The petiole sinus has slightly overlapping lobesand V-shaped at the base. There are no particularly distinguishingfeatures with respect to the petiole sinus. The lobes forming the upperleaf sinus are slightly overlapping. The base of the upper leaf sinus isV-shaped. Anthocyanin coloration is absent on the main vein on both theupper or lower blade surfaces.

FLOWERS

The flowers are fertile, of average size and are hardy. They are ofaverage length and plump in shape. Fruit is produced at the 5th to 6thnode.

In Wasco, Calif., flowers attained first and full bloom between May 10,1991 and May 21, 1991, generally the same as the Sugraone, 8 days beforeThompson seedless and slightly earlier than most other similar varietiesin the growing in this area. Flowers are of average size and length,usually 6 per cane and about 36 per vine. Flowers are hermaphroditic.

FRUIT

The fruit of the new variety ripens about 2 days before fruit of theSugraone variety and about 15 days ahead of the Thompson Seedlessvariety.

Fruit is suitable for market use and has average shipping qualities; ithas average resistance to insects and diseases.

The size of the berry clusters (excluding the peduncle) is average;weighing on the average about 348 grams. The loosely compact, conicalcluster usually bears an average of about 67 to 68 berries.

The peduncle is of average length and shows weak lignification. Pedunclecolor is near Yellow-Green 145C.

Berries are large, but vary in size and are of cylindrical shape with acircular cross section (on average the longitudinal axis is about 26-27mm long, and the horizontal axis is about 17 mm in diameter). The brushusually pulls out of the berry without the pedical. Berries are nearYellow-Green 151 A in color. When ripe, the berries have a sweetsubacidic taste and when very ripe a very faint muscat taste can benoted.

The skin is of average thickness, crisp in texture, is tenacious to theflesh, rough and without reticulation.

Table 1 below provides a comparison of the cluster count, clusterweight, berry weight and berry dimensions of Sugratwelve grapes andSugraone grapes.

                  TABLE 1                                                         ______________________________________                                        CHARACTERISTICS OF SUGRATWELVE VS.                                            SUGRAONE                                                                                   SUGRATWELVE SUGRAONE                                                          MEAN +      MEAN +                                                            STANDARD    STANDARD                                                          DEVIATION   DEVIATION                                            ______________________________________                                        Cluster count/vine                                                                           31.5 ± 10.7                                                                              38.8 ± 7.6                                    Cluster weight (grams)                                                                       348 ± 65   565 ± 104                                     (pounds)       0.77 ± 0.14                                                                              1.24 ± 0.23                                   Berry weight (grams)                                                                         5.14 ± 0.85                                                                              5.46 ± 0.95                                   Berry length (millimeters)                                                                   26.6 ± 1.6 22.6 ± 1.24                                   Berry diameter 17.2 ± 0.59                                                                              19.21 ± 0.73                                  (millimeters)                                                                 ______________________________________                                    

Table 2 below tabulates the sugar contents and titratable acid ofSugratwelve grapes and sugraone grapes over a two week ripening period.

                  TABLE 2                                                         ______________________________________                                        SUGAR AND TITRATABLE ACID LEVELS OF                                           SUGRATWELVE VS. SUGRAONE                                                      SUGRATWELVE         SUGRAONE                                                        SUGAR      ACID       SUGAR    ACID                                     DATE  °BRIX                                                                             G/100 ML   °BRIX                                                                           G/100 ML                                 ______________________________________                                        7-12-91                                                                             14.9 ± 0.78                                                                           0.76 ± 0.08                                                                           13.5 ± 1.1                                                                          0.88 ± 0.07                           7-16-91                                                                             16.0 ± 0.75                                                                           0.66 ± 0.07                                                                           14.2 ± 1.1                                                                          0.71 ± 0.07                           7-19-91                                                                             16.4 ± 0.67                                                                           0.56 ± 0.05                                                                           14.8 ± 1.0                                                                          0.59 ± 0.06                           7-22-91                                                                             16.8 ± 0.66                                                                           0.52 ± 0.05                                                                           15.4 ± 1.1                                                                          0.55 ± 0.06                           7-26-91                                                                             17.2 ± 0.61                                                                           0.49 ± 0.04                                                                           15.9 ± 1.1                                                                          0.52 ± 0.06                           ______________________________________                                    

What is claimed is:
 1. A new variety of grapevine cv. Sugratwelve,substantially as herein shown and described.